1. Field of the Invention
The present invention relates to medical devices, and, in particular, to a retractor for harvesting a blood vessel, which, in turn, is used in connection with an ongoing or subsequent surgical procedure. More particularly, the present invention provides such a retractor that is capable of defining and illuminating a subcutaneous working space to ameliorate accessibility to, and to facilitate visualization and harvesting of one or more blood vessels (e.g., saphenous vein) for grafting/transplantation in connection with a surgical procedure (e.g., coronary bypass surgery).
2. Description of Related Art
In certain surgical procedures, it is necessary to remove a portion (or even the entirety) of a patient""s blood vessel for use in another, often remotely located part of that, or a different patient""s body. For example, it is known to remove/excise some or all of a patient""s saphenous vein, cephalic vein, basilic vein, radial artery, or mammary artery for transplantation in connection with a coronary bypass surgical procedure. Once transplanted, the removed section (or entirety) of the vein/artery functions as a graft that replaces both the coronary arteries, which, as a result of aging and/or disease, have become blocked by plaque deposits, stenosis, or cholesterol, thus severely inhibiting their ability to supply life-sustaining blood to the patient""s heart.
In some instances, these blockages can be treated with angioplasty, atherectomy or stent placement, and, therefore, coronary bypass surgery is not warranted. Quite often, however, a coronary bypass is required because these treatment methods are either contraindicated, or have proven incapable of removing such blockages from coronary arteries.
According to current coronary bypass surgery techniques, a blood vessel is harvested from elsewhere within a patient""s body and grafted into a locus between the patient""s aorta and the coronary artery beyond the point of blockage. It is preferred to use a blood vessel taken from the patient undergoing bypass surgery, since he/she is a ready source of suitable vessels that will not be rejected by his/her own body after transplantation.
Currently, the saphenous vein (which is located in a patient""s leg) is the most commonly used graft/substitute for small arteries such as the coronary arteries. This is likely because the saphenous vein is typically 3 to 5 mm in diameter (i.e., about the same size as the coronary arteries), and further, because the venous system of the leg is sufficiently redundant, such that following removal of the saphenous vein, other veins that remain within the patient""s leg are adequate to provide return blood flow.
Harvesting the saphenous vein entails making one or more incisions in a patient""s leg, then using a retractor to reach beneath and lift the skin to expose underlying subcutaneous/connective tissue. This tissue is then pulled away to reveal the saphenous vein, which is then carefully removed.
Although handling of the saphenous vein should be kept to a minimum, it must be separated from the connective tissue, and that requires some contact with the vein. Thus, after the saphenous vein is exposed, medical personnel grasps it with their fingers while stripping off the surrounding tissues with dissecting scissors or other scraping instruments. The medical personnel then uses their fingers and/or blunt dissection tools to separate the vein from the surrounding tissue.
Once the saphenous vein has been completely separated from the surrounding tissue and the tributary veins that feed into the saphenous vein, medical personnel cut the proximal and distal end portions of the vein, and remove the vein from the leg. The saphenous vein is then prepared for implantation into the graft site, and the incision(s) made in the patient""s leg is/are closed (e.g., by suturing or with staples).
Until recently, only one incision was made to access the saphenous vein. This incision was quite longxe2x80x94spanning a patient""s groin to at least their knee, and often to their ankle.
Making this long, xe2x80x9cfilet-likexe2x80x9d incision inherently presents a serious risk of injury to the medial lymph bundle and/or to nerves located within the patient""s leg, as well as a realistic risk of infection to the incision site. Moreover, the healing process associated with this xe2x80x9cfilet-likexe2x80x9d incision is quite protracted (often more prolonged than the healing time associated with the incision(s) made in the patient""s chest in furtherance of the coronary bypass) and very painful, especially if the patient has circulation problems in their extremities. Ultimately, in fact, the incision often does not heal properly, and, in such instances, requires medical attention and/or an invasive procedure (e.g., corrective surgery) to enable proper healing thereof.
As indicated in U.S. Pat. No. 6,193,651 to DeFonzo, U.S. Pat. No. 6,228,025 to Hipps et al, and U.S. Pat. No. 6,322,499 to Evans et al., however, techniques now exist that allow the saphenous vein to be harvested by making several small (i.e., about 2.5 inches to 4 inches in length) transverse incisions on the proximal thigh, at the level of the knee joint, and, optionally, at the inner malleolus.
In accordance with these techniques, a retractor is inserted into each of these incisions to define, access and illuminate subcutaneous space. The retractor is used to form a skin bridge to allow for retraction of at least some of the fat and tissue surrounding the saphenous vein, which is then harvested according to, for example, the technique described above, but without the risks/drawbacks associated with making a xe2x80x9cfilet-likexe2x80x9d incision.
Although such risks/drawbacks are avoided by making comparatively smaller incisions in connection with saphenous vein harvesting procedures, some in the art believe that other drawbacksxe2x80x94ones that were not prevalent when saphenous vein harvesting was performed by making the long, xe2x80x9cfilet-likexe2x80x9d incisionxe2x80x94can arise by virtue of making these small incisions and/or due to the design of the retractors used in connection with such procedures.
For example, some believe the harvesting process has become complicated by the need to utilize equipment that is small enough to fit into both these small incisions and the subcutaneous space. In particular, they believe that vessel harvesting equipment (e.g., a retractor) should have certain dimensions in order to easily and confidently manipulate a patient""s skin and tissue, but also that it is currently not possible for the equipment to have such dimensions, and yet still be able to fit within these small incisions and the subcutaneous space.
One group of patients that would appear to be most affected by these alleged equipment-related limitations are obese patients. Because obese patients tend to have increased quantities of subcutaneous fat and/or tissue in their legs, it is perceived that equipment that is able to fit within small incisions cannot manipulate such fat and tissue to an extent that allows for proper visualization of the subcutaneous space.
Thus, the procedure for harvesting a saphenous vein from obese patients potentially creates a tradeoff that, at least in the minds of some, renders the procedure contraindicated for such patients. This is troubling because it suggests that the obese (who, at present, represent a significant percentage of those who require coronary artery bypass surgery) may have fewer options for vessels that may be harvested for grafting in connection with a coronary artery bypass procedure.
Yet another perceived problem with current techniques for the harvesting of vessels (e.g., the saphenous vein) is that some believe the design of retractors used in connection with harvesting techniques may impede optimal visualization of at least some of the subcutaneous space.
As noted above, such retractors are designed to reach beneath and lift a patient""s skin to expose underlying, connective tissue and, in doing so, to create subcutaneous space near the vessel to be harvested.
For example, in furtherance of usage of the retractor (see FIG. 1) described and depicted in U.S. Pat. No. 6,228,025 to Hipps et al. to harvest a patient""s saphenous vein, the retractor 210 is grasped at its handle 220, and placed within an incision in a patient""s leg in a direction such that the proximal end 211 of the retractor enters the incision (and leg) first, followed by the remainder of its blade sections 230, 240.
Thus, when the retractor 210 is properly positioned beneath a patient""s skin, the proximal end 211 of the retractor is located farthest (as compared to the remainder of the blade) from the incision. Once the retractor 210 has been inserted as such, the handle 220 is arched/lifted to, in turn, lift the entire blade, thus defining the subcutaneous space.
As described in U.S. Pat. No. 6,228,025 to Hipps et al., use of the retractor 210 allows for the creation and visualization of enough subcutaneous space to quickly and reliably perform vessel harvesting. Because of the design of the retractor 210, however, the entirety of this subcutaneous space might not be able to be optimally visualized. Most notably, the subcutaneous space defined at or near the proximal end 211 of the retractor 210 may be especially difficult to visualize. This is because the overlying skin and tissue tends to collapse atop and xe2x80x9cflap overxe2x80x9d the proximal end 211 of the retractor, thus potentially preventing optimal visualization of the area, especially if the patient is obese and, as such, has increased quantities of underlying tissue and/or fat.
Therefore, a need exists for surgical equipment, particularly a retractor, that is able to fit within the small incisions that are made in a patient in connection with minimally invasive vessel harvesting (e.g., saphenous vein or radial artery) and within the subcutaneous space that is defined under the patient""s skin, but that also can easily and effectively manipulate a patient""s underlying fat and/or tissue (even if the patient has abnormally large quantities thereof, e.g., if the patient is obese) and that can allow for increased visualization of the subcutaneous space defined by the retractor.
The present invention provides a surgical retractor that meets this, and other needs. As shown in the drawings, the present invention provides a retractor for defining, accessing and illuminating a subcutaneous working space near a blood vessel (e.g., the saphenous vein) located within a patient""s body to facilitate safe, reliable and expeditious harvesting of the vessel.
In the contemplated less invasive operation for harvesting a patient""s saphenous vein, medical personnel make 2-3 small (i.e., about 2.5 inches to 4 inches in length) transverse incisions on the patient""s proximal thigh, at the level of the patient""s knee joint and, optionally, at the patient""s inner malleolus. This procedure creates/results in several long skin bridges between the incisions. To expose the length of the saphenous vein, which is beneath the skin bridges, the medical personnel lifts the skin and connective tissue with the illuminated retractor.
Once the retractor is positioned as desired, medical personnel may use an existing external retention device to support the retractor and maintain the skin bridge while they dissect connective tissue from around the blood vessel. The external retention device preferably attaches to a structure (e.g., the table on which the patient lies), and is adjustable in order to attach to a connector on the retractor, and to retain the retractor in the desired position.
The illuminated retractor provides a large, well illuminated surgical field, which preferably extends the substantial length of the retractor within the subcutaneous space. With the saphenous vein exposed and visualized, medical personnel use their fingers and/or blunt dissection tools to separate the vein from the surrounding tissues. When the vein has been completely separated from the surrounding tissue and the tributary veins that feed into the saphenous vein have been clipped or cauterized, the medical personnel cut the proximal and distal end portions of the vein and removes the vein from the leg. After vein removal, the 2-3 small incisions made in the leg are sutured or stapled closed, thus completing the vein harvesting procedure.
The illuminated surgical retractor preferably has a handle member, a first elongate section and a second elongate section. The handle member is contoured to be gripped by medical personnel, and, in a preferred aspect of the invention, is pivotally connected to the first elongate section at the distal end portion of the first elongate section to permit one-handed use of the retractor by medical personnel.
Unless indicated otherwise, the term xe2x80x9cmedical personnel,xe2x80x9d as used herein, is intended to refer to a single individual that has a role in connection with a surgical procedure. The specific medical personnel who performs a given task in connection with the procedure described herewithin is determined based on the particular task, the level of training required to perform the task, and the availability of other medical personnel.
The handle member permits the retractor to be lifted at any desired angle with respect to the axis of the vessel (e.g., the saphenous vein). Application of a pulling force to the handle member results in a corresponding pulling or retraction force being applied to the skin and/or tissue via the first elongate section. This force, in turn, creates/defines subcutaneous space beneath the skin.
In an exemplary aspect of the invention, an elongated rod portion extends from the handle member. The rod portion allows the retractor to be maneuvered into a desired position by medical personnel, and then fixed in this position by clamping or grasping the retractor with the available operating table retention mechanism(s).
The first elongate section (which is preferably made of a metal or alloy) of the retractor has a first elongate proximal end portion, a first elongate distal end portion, a first elongate outer surface, and a first elongate inner surface, and functions to transfer lifting and/or insertion forces from the handle member to the skin bridge of the patient.
In an exemplary aspect of the present invention, the first elongate section has at least one non-uniform dimensional characteristic, e.g., width. Generally, at least a portion of the width of the first elongate section tapers outwardly at a predetermined inclusive angle of taper. Preferably, the width of both sides of the first elongate section tapers outwardly from approximately its proximal tip to its distal end portion, and/or includes one or more inwardly and outwardly tapering winged/flanged sections.
The non-uniform width of the first elongate section enables the retractor to more easily maneuver and support normal or increased quantities of a patient""s underlying fat and tissue, and, therefore, allows for improved visualization of the subcutaneous space defined by the retractor.
The second elongate section, which is preferably made of a transparent material, has a second elongate proximal end portion, a second elongate distal end portion, a second elongate outer surface and a second elongate inner surface, and functions to perform the illumination feature of the present invention.
The second elongate section either has a substantially uniform width (e.g., when the first elongate section includes one or more flanged/winged portions) or a substantially non-uniform width (e.g., when the first elongate section has a tapering width but does not include one or more tapering flanged/winged portions), and is preferably slidable laterally with respect to a portion of the first elongate section and into engagement with the first elongate section such that the first and second elongate sections are substantially adjacent to each other while engaged.
As used herein, reference to the proximal end portion of an element is intended to denote the end portion of an element that is spaced apart from the handle member, and reference to the distal end portion of an element is intended to denote the end portion of an element that is generally adjacent to or closer to the handle member of the present invention.
The first elongate proximal end portion of the first elongate section preferably has a rounded shape or a smoothly radiused pointed shape that allows the retractor to be pushed into any of the transverse incisions. Once so inserted, the retractor can be safely pushed forward underneath the skin, and into/within the connective/subcutaneous tissue.
Additionally, the first elongate proximal end portion of the first elongate section preferably includes an insertion area to receive and retain the proximal end portion of the second elongate section, and to ensure that these sections remain adjacent to each other during the vessel harvesting procedure.
In a preferred aspect of the invention, the insertion area is a substantially U-shaped flap or loop into which the proximal end portion of the second elongate section is laterally, securely insertable.
Although the insertion area should protrude from the first elongate section enough to allow for insertion of the second elongate section therein, it also should provide a low profile extension that does not deter dissection of connective/subcutaneous tissue, and that ensures that the inserted second elongate section will not become dislodged therefrom during the vessel harvesting procedure.
The proximal end portion of the second elongate section preferably has a rounded shape or, alternatively, a smoothly radiused pointed shape. The shape of the second elongate section proximal end portion is selected to allow for insertion thereof into the insertion area of the first elongate section. Its shape also should ensure that the proximal end portion of the retractor (when the first and second elongate sections are connected) can readily penetrate connective/subcutaneous tissue as the retractor is inserted into a small incision and maneuvered into position, and that the proximal end portion of the second elongate section will be securely retained in the insertion area during the vessel harvesting procedure.
Moreover, the proximal end portion of the second elongate section also is preferably configured/shaped to direct light forwardly of the retractor (in addition to the light that emanates from, and extends the substantial length of the retractor) during use to allow for improved visualization of the subcutaneous space in connection with the vessel harvesting procedure of the present invention.
The retractor of the present invention also preferably includes a dissecting tip, which extends from the proximal end portion of the first elongate section. This tip allows medical personnel to use the retractor as a dissecting device while the retractor is being maneuvered into, around and/or through the connective and subcutaneous tissue surrounding the vessel (e.g., saphenous vein). The tip may include serrations thereupon to assist in the dissection of the tissue, and in retaining the retractor in its desired position during the vessel harvesting procedure.
In order to enhance the reflective qualities of the illuminated retractor, the first elongate inner surface of the first elongate section may include a mirrored surface thereon. Also, the second elongate inner surface of the second elongate section may have a machined or molded (e.g., injection molded) micro-lens surface thereon that refracts light forwardly at a desired angle.
In another alternate aspect of the invention, the second elongate inner surface may be reflective, in order to direct illumination outwardly from the second elongate outer surface. Furthermore, the second elongate section may be constructed so as to reflect the illumination forwardly from the second elongate section in order to illuminate the skin bridge forwardly of the illuminated surgical retractor.
For example, the second elongate section may be formed so that the light is transmitted at a forward angle that is preferably between about 15xc2x0 and 75xc2x0, and, more preferably, between about 30xc2x0 and 60xc2x0 relative to the second elongate section, and so that illumination may also be scattered to the sides of the retractor as desired.
A preferred form of the retractor also includes a connector, preferably a twist type connector, between the handle member and the first and second elongate sections. This allows for a simple connection (e.g., a one-quarter turn) to reversibly but assuredly secure the first elongate section to the handle with confidence that these components will remain attached as the skin bridge is defined/created and maintained.
The connector also connects the handle member to the second elongate section to ensure that the light energy travels from the light source, through the handle member, and into the second elongate section. The light energy fills the second elongate section such that light energy is radiated from the second elongate section into the subcutaneous space defined by the retractor.
In this manner, light can be provided from the light source via the optical cable to the illumination input end portion of the second elongate section so that the second elongate section is illuminated, thus resulting in an illuminated surgical field.
A further feature of a preferred form of the present invention is that the distal end portion (or heel portion) of the illuminated retractor is formed to shield all nearby medical personnel from the light created by the distal end portion of the second elongate section. Additionally, the first elongate section may include a side channel in a shaft portion thereof to allow a shaft shaped portion of the second elongate section to be inserted therethrough, thus allowing the second elongate section to be replaceably mounted onto the first elongate section as desired.
A further feature of the illuminated retractor of the present invention is that at least a portion of the shaft shaped portion and/or the distal end portion of the second elongate section is preferably spaced apart from at least a portion of the shaft portion and/or the distal end portion of the first elongate section to ensure that there is no heat buildup between these elements of the retractor.
Still other features of a preferred form of the retractor of the present invention are that the light cable passes through the handle member of the retractor, and that a portion of the handle member may be formed to allow the light generated by the light cable to be observed through the body of the handle member. These features enable medical personnel using the retractor to readily determine whether or not the light source for the retractor is in operation.
Additionally, in a further preferred aspect of the invention, the retractor may include a second connection that may be used to connect a standard light cable at the top of the handle member to a shortened light cable in the handle member of the retractor, so that the handle member and elongate members may be packaged and/or sterilized separately. Alternately, the light cable may be allowed to pass through the handle member for direct connection to the light source and the second elongate member as desired.
Still other aspects, embodiments and advantages of the present invention are discussed in detail below.